Internal audits, sometimes called “first-party audits”, are conducted by, or on behalf of, the organization itself for internal purposes and can form the basis of an organization’s self- declaration of conformity. External audits include what are generally termed “second-” or “third-party audits”. Second-party audits are conducted by parties having an interest in the organization, such as customers, or by other persons on their behalf. Third-party audits are conducted by external independent organizations. Such organizations provide certification or registration of conformity with requirements such as those of ISO 9001 and ISO 14001:1996. When quality and environmental management systems are audited together, this is termed a “combined audit”. When two or more auditing organizations cooperate to audit a single auditee jointly, this is termed “joint audit”.